Let me say up front that I don’t see any compelling reason to believe that if you’re committed to pursuing collective survivability that you then ought to be committed to diversity tolerance. Sometimes, it seems to me, a social identity group really is best served by everyone knowing exactly what role that they each should be playing.
But other times the best survival strategy would seemingly be to organize ourselves so as 
to facilitate the evolution of a complex adaptive social system capable of generating emergent intelligence and behavior, i.e., greater than the sum of our parts.
Such social organizations are necessarily composed of proscriptive (means-oriented) norms that foster the required diversity that sustains a complex adaptive social system.
While ‘liberal democracies’ are, at heart, an expression of this inclination towards a mean-oriented complex adaptive social system, it seems as though the meaning of the phrase ‘tolerance of diversity’ sometimes gets a bit … ‘lost in translation’.
‘Tolerance of diversity’ implies that the nature of ‘others’ is regarded as being ‘complex’. The most valued quality of the behavior of others, in such organizations, simply isn’t their predictability or reliability but rather their uniqueness and adaptability. The reality is that this ‘cognitive’ behavior is not even predictable to ‘them’ … given its multi-scale non-linearity, butterfly-like tipping-points, catastrophic cusps and feedback loops. We can only engage diverse others with curiosity … even as the engagement itself influences both us and them.
This is very much in contrast to end-oriented role-based social organizations where interpersonal interactions primarily serve to define expected (role) behavior.
Sometimes we collectively ‘grok’ the nature of this ‘tolerance’ but other times we seem to become proverbially ‘wrapped around the axle’ about what it means … perhaps because ‘real-life’ social identities are almost always, in practice, a dynamic mix of prescriptive and proscriptive norms, which muddies up our collective thinking.
I recently put my finger on one of these ‘axle wraps’ in amongst all the recent churnings regarding election meddling.
We don’t seem to have any problem collectively sensing that the larger outside world shouldn’t be encouraged to influence the process we use to 
define ‘our’ collective story. We recognize that ‘they’ may well want to dictate to us what our story ought to be … but we also recognize that its in the larger group’s interest for us to define our own voice (as well as being in our own interest). We’re rightly upset about Russia’s intent to influence our election but we’re even more rightly upset that some actors, within our nation, may well have intentionally encouraged that behavior.
But here’s where the blindness factors in: If it serves the collective interest for the constituents to define their own voices, free of external influence, then how can it be in our nation’s interest for national level voices to be both attempting to influence local elections and to be welcomed to do so by the various competing local stories? Yet this is exactly what’s happening all across the nation from both sides of the aisle and everywhere in between … virtually without any skeptical reflection.
What’s good for the goose is good for the gander. If collective intelligence emerges in the context of diversity tolerance then let us guard the right and obligation for each or us to find our own voice; free of external influence/coercion!
One final note: Too often lately I’ve seen pundits, on both sides of the aisle, wring their hands over how a liberal democracy, which embraces tolerance of diversity, can ever 
authentically be intolerant. The answer, it seems to me, is really quite simple: liberal democracies are no less willing to sacrifice to defend their boundaries than is any goal-oriented autocracy … it’s just that the boundaries, to be defended, are process-oriented. Tolerance of diversity has never been a carte blanche; there’s always been a corollary. More fully the norm could be phrased ‘tolerance of all diversity except intolerance of diversity’. That is truly the foundation of a liberal complex adaptive democracy.